The present invention relates to a shaft lock apparatus that is included in a member, such as a display device of a notebook personal computer, a notebook word processor, a mobile terminal apparatus, or an LCD monitor, or a rotatable lid of various machines, or the like, whose tilt angle is necessary to be adjusted.
FIG. 21 illustrates a conventional shaft lock apparatus stated in Japanese Utility Model Publication No. 2547422. This shaft lock apparatus is composed of a slider washer 110, a rotating member 120, a friction washer 130, a spring washer 140, and a retaining washer 150, all of which are coaxially installed onto a shaft 100. Moreover, in the rotating member 120 there is formed a fitting plate 123, which is to be affixed to the main body of the device supporting a display panel or the like so as to be capable of being rotated.
The shaft 100 is furnished with a flange 101, a fitting-axis portion 102 that extends from one side of the flange 101 and whose tip end is noncircular in shape, and a connecting-axis portion 103 that extends from the other side of the flange 101 and that is circular shaped. This shaft 100, whose fitting-axis portion 102 is attached to a mating member, such as a display panel, rotates with the rotation of the mating member as one united body.
The connecting-axis portion 103 passes through the slider washer 110, the rotating member 120, the friction washer 130, the spring washer 140, and the retaining washer 150, and in each of the slider washer 110, the rotating member 120, the friction washer 130, the spring washer 140, and the retaining washer 150, the axial holes 111, 121, 131, 141, and 151 are formed so that the aforementioned the connecting-axis portion can pass through them. By caulking the passing-end portion of the connecting-axis portion 103 that passes through these members, the slider washer 110, the rotating member 120, the friction washer 130, the spring washer 140, and the retaining washer 150 are put together in such a way that the spring washer 140 and the retaining washer 150 closely contact with each other, being subject to pressure by the spring washer 140. Because this pressure produces friction torque, the shaft 100 and the rotating member 120 are held at any intended angle, and as a result the tilt angle of the display panel can be adjusted.
In such a conventional shaft lock apparatus, it is not specified which member rotates, because any member can rotate against the shaft 100 at the time of the relative rotation of the shaft 100 and the rotating member 120. Consequently, the region where friction arises cannot be specified, and the friction torque varies in the different rotating members. This makes it impossible to secure stable friction torque. Also, because of the complicated structure of the apparatus, the number of the members that cause friction torque is large and it is difficult to assemble the apparatus.
The object of the present invention, based on the consideration of the aforementioned problems of the conventional apparatus, is to provide a shaft lock apparatus that is capable of causing stable friction torque and that is capable of keeping any intended tilt angle by a simple structure.
In order to achieve the above-mentioned object, the invention set forth in claim 1 is characterized such that it consists of:
(1) a rotating member, through which the shaft passes in a condition of free rotation, and
(2) an elastic pressure member that has (a) a belt-like flat portion of a specified width, and (b) rising portions that bend in the same direction from both sides of the flat portion, and whose flat portion is arranged in a direction such that the flat portion directly contacts the rotating member, or
(3) an elastic pressure member that has a curved shape, and is arranged in such a way that its central part directly contacts the rotating member; and such that it is furnished with
(1) said elastic pressure member, through which the aforementioned shaft passes, and which keeps the angle between the rotating member and the shaft at any desired degree by pressing the rotating member; and
(2) a retaining plate, through which the aforementioned shaft passes under a condition such that the shaft""s rotation is restricted, and which presses said elastic pressure member onto the rotating member.
In this invention, because the rotation of the elastic pressure member is bound against the shaft, the elastic pressure member rotates as one united body with the shaft when the relative rotation of the shaft and the rotating member occurs. In this rotation, the angle between the rotating member and the shaft can be kept at any desired degree because the friction torque arises due to the elastic pressure member pressing against the rotating member. In such a structure, it is possible to stabilize the friction torque because the elastic pressure member always rotates together with the shaft. In addition, because the number of the parts is small the structure is simple, and therefore assembly is easy.
The elastic pressure member in this invention is either
(1) an elastic pressure member that has (a) a belt-like flat portion of a specified width, and (b) rising portions that bend in the same direction from both ends of the flat portion, and that is arranged in such a direction that its flat portion directly contacts the rotating member, or
(2) an elastic pressure member that has a curved shape, and is arranged in such a way that its central part directly contacts the rotating member.
When the elastic pressure member that has rising portions on both sides of its flat portion presses against the rotating member, the borders between the flat portion and the rising portions linearly contact the rotating member, whereby friction torque is produced. By this linear contact, the desired contact length can be ensured, and stable friction torque also can be obtained because the two portions on the two sides of the flat portions contact the rotating member. When the shaft rotates under this condition, the elastic pressure member rotates together with the shaft, and therefore the borders of the flat portion and the rising portions whirl around the shaft. Thus, because the borders of the flat portion and the rising portions contact with the rotating member in a circle track, the area of contact between the rotating member and the elastic pressure member increases, whereby abrasion of the two members is decreased and their durability improves.
In the case of an elastic pressure member that has a curved shape, its central part contacts the rotating member in such a way that the shape of the contacting area becomes circular, whereby friction torque is produced. Therefore, stable friction torque can be obtained. In this case, when the shaft rotates, the elastic pressure member rotates together with the shaft as one body, where the contact area between the shaft and the elastic pressure member has a circular shape, so the friction between the two members is decreased and their durability is improved.
The invention set forth in claim 4 is characterized such that it consists of
(1) a rotating member, through which the shaft passes in a condition of free rotation, and
(2) an elastic pressure member that has (a) a belt-like flat portion of a specified width, and (b) rising portions that bend in the same direction from both sides of the flat portion, and whose flat portion is arranged in such a direction that the flat portion directly contacts the rotating member, or
(3) an elastic pressure member that has a curved shape and that is arranged in such a way that its central part directly contacts the rotating member; and such that it is furnished with
(1) an elastic pressure member, through which the aforementioned shaft passes under a condition such that the shaft""s rotation is bound, and which keeps the angle between the rotating member and the shaft at any desired degree by pressing against the rotating member;
(2) a friction plate through which the aforementioned shaft passes under a condition such that the shaft""s rotation is bound, and that is superposed on the aforementioned rotating member, and
(3) a retaining plate through which the aforementioned shaft passes under a condition such that the shaft""s rotation is bound, and that presses against said elastic pressure member onto the rotating member.
This invention includes a structure such that either (1) the friction plate is placed between the shaft and the rotating member and the elastic pressure member is placed so that the rotating member is placed between the elastic member and the friction plate, or (2) the elastic pressure member is placed between the shaft and the rotating member and the friction plate is placed so that the rotating member is placed between the friction plate and the elastic pressure member.
In the invention set forth in claim 4, the elastic pressure member and the friction plate rotate together with the shaft as one united body in the relative rotation of the shaft and the rotating member. Consequently, friction torque arises between the elastic member and the rotating member while friction torque arises between the friction plate and the rotating member. Accordingly, it is possible to stabilize the fiction torque because extensive friction torque arises. Also, because of the small number of the parts, a simple structure is enabled. In addition, because the friction plate is furnished, durability improves.
In this invention, the elastic pressure member is either
(1) an elastic pressure member that has (a) a belt-like flat portion of a specified width, and (b) rising portions that bend in the same direction from both sides of the flat portion, and that is arranged in a direction such that its flat portion directly contacts the rotating member, or
(2) an elastic pressure member that has a curved shape and that is arranged in such a way that its central part directly contacts the rotating member.
Therefore, the area of the contact between the elastic pressure member and the rotating member is large, so that friction torque is stabilized and the abrasion of the two members is decreased and their durability improves, just as the invention set forth in claim 1.
The invention set forth in claim 5 is characterized such that it consists of
(1) a friction plate, through which the shaft passes in a condition of bound rotation;
(2) a rotating member, through which the shaft passes in a condition of free rotation;
(3) an elastic pressure member that has (a) a belt-like flat portion of a specified width, and (b) rising portions that bend in the same direction from both sides of the flat portion, and that is arranged in a direction such that its flat portion directly contacts the rotating member, or
(4) an elastic pressure member that has a curved shape and that is arranged in such a way that its central part directly contacts the rotating member; and such that it is furnished with
(1) said elastic pressure member, through which the shaft passes in a condition of bound rotation; and
(2) a retaining plate, through which the shaft passes in a condition of bound rotation;
and such that all of which are fit together in piles on the shaft in such a consecutive order; and
such that by caulking the passing end of the shaft that passes through the retaining plate, the angle between the rotating member and the shaft is kept at any desired degree by the elastic pressure member pressing against the rotating member.
In this invention the friction plate, the rotating member, the elastic pressure member, and the retaining member are in a superposed condition by caulking the passing end of the shaft after the friction plate, the rotating member, the elastic pressure member, and the retaining member are fit on the shaft in the aforementioned consecutive order. Under this condition, because the friction plate and the elastic pressure member rotate together with the shaft, friction torque arises between the elastic pressure member and the rotating member while friction torque arises between the friction plate and the rotating member. Accordingly, the friction torque is stabilized, and the angle between the rotating member and the shaft can be maintained with certainty.
In this invention, the elastic pressure member is either
(1) an elastic pressure member that has (a) a belt-like flat portion of a specified width, and (b) rising portions that bend in the same direction from both sides of the flat portion, and that is arranged in a direction such that its flat portion directly contacts the rotating member, or
(2) an elastic pressure member that has a curved shape and that is arranged in such a way that its central part directly contacts the rotating member.
Therefore, the area of the contact between the elastic pressure member and the rotating member becomes large, and therefore friction torque is stabilized, the friction between the members is decreased and durability is improved, just as the invention set forth in claim 1.
The invention set forth in claim 2 is any invention stated in claims 1, 4 and 5 that is characterized such that at least two of the aforementioned elastic pressure members are placed along the aforementioned shaft.
In this invention, by superposing a plurality of the elastic pressure members on the both sides, it is possible to increase flexure volume in all of the elastic pressure members and to extensively adjust the friction torque. Also, it is possible to obtain high friction torque because superposing a plurality of the elastic pressure members in the same direction increases the pressing of the pressure members against the rotating member.
The invention set forth in claim 3 is any invention stated in the claims 1, 4 and 5 or 2 that is characterized such that a lubricant-dispensing hole that supplies lubricant is formed in the aforementioned elastic pressure member.
In this invention the durability improves because of the lubricant from the lubricant-dispensing hole.